There are a large number of diagnosed cases of deep vein thrombosis, DVT, in the United States annually. There are also a large number of fatal cases of pulmonary embolism, PE, many of which can be prevented with appropriate measures, such as pharmacological or mechanical. Prolonged sitting, such as when traveling or working long hours, can aggravate or promote DVT or PE. It can also cause ankle edema and leg discomfort. Studies have indicated that about one-fifth of the sudden natural deaths associated with commercial air travel that were brought to the London Coroner from Heathrow Airport were due to pulmonary embolism. There is a need for a device that helps to stimulate blood flow so as to prevent DVT and PE during the above mentioned circumstances. One such device is disclosed in U.S. Pat. No. 5,643,331 entitled "Method and Device For Prevention of Deep Vein Thrombosis" issuing to Katz on Jul. 1, 1997, which is herein incorporated by reference. Therein disclosed is an electrical stimulator generating a square wave pattern having a controllable duration ranging from 0.1 to 0.3 milliseconds, a controllable frequency ranging between 0.001 to 0.5 cycles per second, and a controllable intensity ranging from 1 to 20 milliamperes. An electrode is positioned externally at or near the tibial nerve at the popliteal fossa to deliver the electrical signal. This signal stimulates the nerve, causing a muscle contraction which helping to stimulate blood flow. The increased blood flow helps in preventing deep vein thrombosis, ankle edema, and venostasis. Additionally, there are numerous transcutaneous electric nerve stimulating devices, TENS units, used to control pain. There are also similar muscle and neurological stimulating devices, MANS units, also used to control or manage pain. All of these devices deliver relatively high frequency stimuli, for example 25 to 50 Hertz. They are generally not tolerated well by patients, especially when used for relatively long periods of time. Additionally, these devices are not completely suitable for the prevention of DVT or PE. Accordingly, while these units used for pain management or control are similar, they are not suited to relatively long term use and self-application by a patient for the prevention of DVT, orthostatic hypotension, PE ankle edema and leg discomfort. Therefore, there is a need for a device and method of application that can easily be self-administered by a patient during extended periods of sitting or inactivity, for example during traveling in a car or a plane, or sitting for many hours while working to help prevent DVT, PE ankle edema and leg discomfort. Additionally, there is a need for a device that is self adjusting preventing the need for a patient to determine appropriate settings. Additionally, there is a need for a device that will sense the muscle contraction and will not operate during on going muscle activity.